Robotic cleaner having distance sensors for use in estimating a velocity of the robotic cleaner

Abstract

A robotic cleaner may include a body, one or more driven wheels configured to urge the body across a surface to be cleaned, one or more distance sensors disposed at least partially within the body such that the one or more distance sensors face the surface to be cleaned and a processor. The one or more distance sensors may be configured to output a measure of a detection distance that extends in a direction of the surface to be cleaned. The processor may be configured to determine whether an abnormality has been detected based, at least in part, on the measure of the detection distance and may be configured to determine a first velocity estimate based, at least in part, on the detection of the abnormality.

What is claimed is: 
     
       1. A robotic cleaner comprising:
 a body; 
 one or more driven wheels configured to urge the body across a surface to be cleaned; 
 a range finder, the range finder being configured to measure a distance to one or more obstacles in a movement direction of the robotic cleaner; 
 one or more distance sensors disposed at least partially within the body such that the one or more distance sensors face the surface to be cleaned and being configured to output a measure of a detection distance that extends in a direction of the surface to be cleaned; and 
 a processor configured to:
 determine whether an abnormality has been detected based, at least in part, on the measure of the detection distance; 
 determine a first velocity estimate based, at least in part, on the detection of the abnormality; and 
 determine a second velocity estimate based, at least in part, on a rate of change of the measured distance to one or more obstacles in the movement direction of the robotic cleaner. 
 
 
     
     
       2. The robotic cleaner of  claim 1 , wherein the processor is further configured to compare the detection distance to a threshold to determine whether the abnormality has been detected. 
     
     
       3. The robotic cleaner of  claim 1 , wherein the one or more distance sensors include a plurality of distance sensing pixels. 
     
     
       4. The robotic cleaner of  claim 3 , wherein the abnormality is sequentially detected by at least two of the distance sensing pixels such that the abnormality can be tracked as the robotic cleaner passes over the abnormality. 
     
     
       5. The robotic cleaner of  claim 1 , wherein the one or more distance sensors include a first distance sensor spaced apart from a second distance sensor. 
     
     
       6. The robotic cleaner of  claim 5 , wherein the first and second distance sensors are spaced apart along an axis that extends substantially parallel to a direction of movement of the robotic cleaner. 
     
     
       7. The robotic cleaner of  claim 6 , wherein, the first velocity estimate of the robotic cleaner is based, at least in part, on a differential detection of the abnormality by each of the first and second distance sensors. 
     
     
       8. The robotic cleaner of  claim 1 , wherein the second velocity estimate is compared to the first velocity estimate to generate a composite velocity estimate. 
     
     
       9. A robotic cleaner comprising:
 a body; 
 one or more driven wheels configured to urge the body across a surface to be cleaned; 
 one or more distance sensors disposed at least partially within the body and configured to output a measure of a detection distance that extends in a direction of the surface to be cleaned, the one or more distance sensors including a plurality of distance sensing pixels; and 
 at least one processor configured execute one or more instructions stored in at least one memory, upon executing the one or more instructions the processor is configured to cause the robotic cleaner to carry out operations comprising:
 detecting an abnormality disposed between the body and the surface to be cleaned using the one or more distance sensors; 
 tracking the abnormality over a predetermined distance by sequentially detecting the abnormality using at least two of the distance sensing pixels; 
 measuring a time elapsed while tracking the abnormality over the predetermined distance; and 
 generating a first velocity estimate for the robotic cleaner based, at least in part, on the predetermined distance and the time elapsed. 
 
 
     
     
       10. The robotic cleaner of  claim 9 , wherein detecting the abnormality includes comparing the measure of the detection distance to a threshold. 
     
     
       11. The robotic cleaner of  claim 9  further comprising a range finder, the range finder being configured to measure a distance to one or more obstacles in a movement direction of the robotic cleaner. 
     
     
       12. The robotic cleaner of  claim 11 , wherein the operations further comprise generating a second velocity estimate based, at least in part, on a rate of change of the measured distance to one or more obstacles in the movement direction of the robotic cleaner. 
     
     
       13. The robotic cleaner of  claim 12 , wherein the operations further comprise generating a composite velocity estimate based, at least in part, on the first and second velocity estimates.